Finding the Fourth Proportional to 1,724.45, 2,379.81 and 978.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,724.45 : 2,379.81 = 978.50 : x
2. Step 2: Convert to fraction form
   1,724.45/2,379.81 = 978.50/x
3. Step 3: Cross multiply
   1,724.45x = 2,379.81 × 978.50
4. Step 4: Simplify right side
   1,724.45x = 2,328,644.09
5. Step 5: Solve for x
   x = 2,328,644.09/1,724.45
6. Step 6: Final answer
   x = 1,350.37